Screening machine



Jan. 5, 1943. A. L. ADRIANSON SCREENING MACHINE Filed Nov. 15, 19:9

3 Shasta-Sheet 1 Jan. 5, 1943.

A. L. ADRiANSON SCREENING momma Filed Nov. 15, 1939 3 Sheets-Sheet 2 Jan. '5, 1943. A. L ADRmN' QN 2,307,098

SCREENING MACHINE Filed Nov. 15, 1939 3 Sheets-Shgfii .5

' five]? i v aggdj, QOZZ'QZZJ OZZ Patented Jan. 5, 1943 UNITED STATES r ar OFFICE Claims.

This invention relates to screening machines, and more particularly to such a machine which is durable, efiicient, adaptable to a Wide variety of uses and has a large capacity for its size and 'Although the screening machine disclosed herein maybe madeinsizes to suit particular applications and purposes, the structure is such that a relatively, small and portable machine is suited to the screening or sifting of substances such as dry sand, damp mould-ing sand, compost, chemicals and pigments. Also, in addition 'to having large capacity as compared to the size and weight of the machine, the-structure is such that the screens are easily and quickly changeable for varying the uses, and during use the screen-is secured in such a way that the life thereofis prolonged.

It is an object of this invention to provide a screening machine having relatively large screeningcapacity compared to size'and weight'of the machine.

Anoth r object of thisinvention is to provide a screening machine in which the screens are easily interchangeable and the screen being used is held in such a way that whipping and breaking of the screen are minimized.

Another object of this-invention is to provide a screening machine having anunobstructed screensurface through whichmaterials are sifted and elements'cooperating withthe screen for increasing-the speed of screening'and' the capacity of-the machine. r

Anotherobject of this invention is to provide ascreening machinewhich is unitary in structure and readily movable.

Other-objects and advantages of this invention willbeapparent from the following description of the structure and operation'of the disclosed embodiment thereof having reference to the accompanying drawings wherein oneform of screeninghrachinewhich embodies the'invention' is clearly shown. 7 I

-In the drawings: 1

. Figs; -1,- 2 and 3 are respectively side, top and and elevations of a screening machine embodying a preferred form of this invention; I

Figs. 4, 5 and 6 are fragmentarysectional views ofportions of the deviceshowninFigs. 1,- 2 --and 3, withfthe section'staken-subst'antially on lines 4-4; '5 5 and 6'6 of Fig.2,respectively, and

viewed in the directions indicated by the arrows,

and

Fig. 7 is a side elevation of apreferred form ofone-part' of the screening machinashowing bolts such as 3| and 32.

the preferred normal disassembled form thereof.

Having particular reference to the drawings, a screen frame 8, having sides 9 and IE1 and ends I l and I2, serves as a receptacle for the material which is to be sifted by the screening machine. The sides 9 and it are secured to angularly disposed portions lla and I2aof the ends H and 12 by rivets or other suitable fastening means, such as l3. Brackets l5 and it are secured to the sides 9 and it respectively by screws such as H, or other suitable fastening means. Curved or semi-elliptical leaf springs l8 and I9 are secured at their mid-portion to the brackets l5 and i6 respectively by bolts or other suitable fasten- The ends of the leaf springs I8 and [9 are secured to and. supported by a base 22 comprising a pair of substantially U-shaped supports 23 and 24 which are secured together at their outer ends by a pair of substantially rigid braces 25 and 26; the springs l8 and I9 being secured at their ends to angularly disposed portions 21 and 28 of the U-shaped support 23 and angularly disposed portions 29- and 30 of, the substantially U-shaped support 24 by Thebraces 25' and 25 are respectively secured to the substantially U- shaped supports 23 and 24 by bolts 33 and 34or other suitable fastening means. By this construction the screen frame- 8 is resiliently supported from the base 22 through the leaf springs I8 and I9.

In the preferred embodiment of this invention, a motor or prime mover 35 is secured directly to the end l2 of the screen frame 8 near the midportion of thatend. The motor or prime mover 35 has a shaft 36-which extends outwardly at each end of the motor and has eccentric or unbalanced weights cr fly Wheels 31' and 38 secured to the extending ends of the shaft. The fly wheels or weights 31 and 38 are preferably unbalanced by being cut away as at 39 and 40 and the cut-away portions are preferably aligned so that the eccentric weights are in phase. Also the motor or prime mover 35 is preferably so positioned that the axis of the shaft 36 is subtsantially perpendicular to the longitudinal planes of the leaf springs i8 and I9. A broad shield 42 is provided for the motor 35, which also serves to clamp the motor onto the screen 'frame, and eccentric weights or fly wheels 37 and 38 by a plate having curely in position and also protects the motor and fly wheels from material being put into the screening machine.

To effect proper balance between the screen frame 8 and the attached motor 35 for stable support through the springs l8 and i9 and to obtain improved vibratory movement of the screen frame 8 as a result of the rotation of the eccentric fly wheels or weights by the motor 35, the brackets l and I6 are preferably disposed nearer to the end 12 which supports the motor than to the end H of the screen frame.

For accomplishing the screening or sifting of material put into the screen frame 8, a screen 65 extends across the screen frame from. end to endand from side to side. This screen 45 may be of any desired mesh and is preferably secured to the screen frame 8 so as to be interchangeable with other screens and so that the upper surface thercof is practically unobstructed. As illustrated in Fig. 4, the screen 66 is looped over angularly disposed portions 47 of strips 48 at each end. Clamping and stretching members 49 and 58 having angularly disposed portions such as 5i extend across each end of the screen frame 8 and engage and secure the screen as at 52. These clamping and stretching members 49 and 56 when drawn toward the ends H and 12 respectively by bolts such as 53 having cooperating wing nuts 55 secure the ends of the screen and stretch it tautly between the ends of the screen frame 5.

Angle irons 66 are secured by rivets b or the like to the screen frame around the bottom thereof so that the marginal portions of the screen 36 rest thereon and to prevent whipping and consequent breaking of the screens during operation of the screening machine, normally bowed strips such as 55 and 56, one of which is illustrated in its normal form in Fig. '7, are secured in position against the sides of the upper surface of the screen by curved and somewhat resilient clamping arms or fingers 58, 59, 6!! and 51. The clamping fingers or arms 58 and 65 are secured to the clamping member 49 by rivets such as 62 or other suitable means. The clamping fingers or arms 59 and 6| are secured to the clamping member 56 by rivets such as 63, or other suitable means. The downward pressure of the flattened out bowed strips 55 and 56 holds the marginal portions of the screen 46 firmly against the supporting angle irons 46 The sides 9 and l 0 of the screen frame 8 preferably extend downwardly below the surface of the screen 46 as illustrated in Fig. 6. Resilient arms 55, 66 and 61 each have an angularly disposed end V such as 63 in Fig. 6 secured to the side l0 below the surface of the screen 56 by bolts 69 having cooperating nuts or other suitable fastening means. These resilient arms extend inwardly with respect to the side ID along and substantially parallel to the lower surface of the screen 46' and in normal spaced relation thereto. The arms 65, 63 and 61 are preferably of different lengths and pads or tappers H, 12 and 13, respectively, are

secured to the extending ends thereof by rivets means as shownat 8|; The arms 75,16 and TI 75 are also preferably of different lengths and it is preferable that the lengths of the oppositely disposed arms 65 and and 61 and H are different.

The operation of the motor is controlled by a switch 83 which is mounted on a bracket 86. The bracket 84 is secured to and supported by the bracket l6 or by any other convenient part of the apparatus.

In the operation of the screening machine herein disclosed, a screen of the proper or desired mesh is first secured to the ends of the screen frame as previously described, while the resilient strips and 56 are removed. After the screen is tautly stretched between the ends, the resilient strips 55 and 56 are inserted between the screen 46 and the clamping arms 58, 59, and 6|. It will be understood of course that the ends of the strips 55 and 56- curve upwardly before they are secured in position beneath the clamping arms 58, 59, 60 and 6|. In changing screens, the resilient strips 55 and 56 are removed and then the screen is released from the clamps at the end of the screen frame. v

Rotation of the eccentric or unbalanced weights or flywheels by the motor 35 causes a vigorous vibration of the screen frame and screenso that material put into the screen frame is rapidly sifted by the screen. The resilience ofthe resilient arms 65,66, 61, 15,16 and l1 and the mass of the padsor tappers H, 12,13, 18,19 and are so proportioned that the-vibration of the screen frame 8 effects the vibration of the resilientarms at a period such that the pads or tappers :continually tap the surface of the screen. The tapping of the screen surface by these padsor tappers increases the speed and efficiency of the .machine and also helps to keep the screen openings clean. Since both surfaces of the-screen are relatively unobstructed, the effective screening area of the screen is maximum. V r

While the embodiment of the present invention which is herein disclosed constitutes a preferred form, it is understood that other forms may be adopted, all coming within the scope of the-claims which follow. 3 A

I claim:

1. In a screening device of the class described, the combination of a screen frame having-an end wall and a pair of laterally spaced sidewalls with a screeninterposed therebetween, said screen frame being resiliently and -non-pivotally-.mounted at its opposite sides at one point only on each side between its ends on long, relatively flat, semielliptical spring supports permitting endwise and up and down and teetering movementof the screen frame, said points of mounting being substantially within a transverse vertical plane passing through the center of gravity of the screen frame, and a rotary vibrator mounted on the end of the screen frame-beyond its aforesaidend wall.

2. In a screening-device of the class described, the combination of a screen frame having an end wall and a pair of laterally spaced side walls-with a screen interposed therebetween,-- said screen frame being interposed between and mounted solely on a pair of laterally spaced-springs which are non-pivotally attached respectively totheside walls of the screen frame at one point only on each side wall between the ends thereof, said points of mounting being substantiallywithin a transverse vertical plane passing throughthe center of gravity of the screen frame,- and a rotary vibrator mounted on the end of the screen frame beyond its aforesaid end wall.-

3. In a screening device of'the class described,

the combination of a support, a screen frame having an end wall and a pair of laterally spaced side walls with a screen interposed therebetween, said screen frame being interposed between and supported solely upon a pair of laterally spaced elongated leaf springs which are non-pivotally attached substantially midway between their ends to the opposite sides of the screen frame at points substantially within a transverse vertical plane passing through the center of gravity of the screen frame, each spring being provided at each end with a core formation by which it is mounted on the aforesaid support, and. a rotary Vibrator mounted on the end of the screen frame beyond its aforesaid end wall.

4. In a screening device of the class described, the combination of a base member, a screen frame and vibrator unit wherein the screen frame has an end wall and a pair of laterally spaced side walls with a screen interposed therebetween and the vibrator is mounted on the end of the screen frame beyond said end wall, and long, relatively flat, semi-elliptical springs interconnecting the base member and the screen frameand vibrator unit resiliently in longitudinally tiltable relation, one spring only on each side of the unit, the unit being non-pivotally supported on the springs substantially in a transverse vertical plane passing through the center of the unit.

5. In a screening device of the class described. the combination of a base member, a screen frame having an end wall and a pair of laterally spaced side walls with a screen interposed therebetween and a rotary vibrator mounted on the end of the screen frame beyond the said end wall, said screen frame being resiliently and non-pivotally supported between its ends solely on springs at points substantially within a vertical transverse plane passing through the center of gravity of the screen frame with its vibrator whereby to permit substantial movement of the screen frame in all directions except transversely.

ALFRED L. ADRIANSON. 

